1. Field of the Invention
This invention relates to webbing locking devices for use in seatbelt systems for locking an occupant restraining webbing, and particularly to a webbing locking device wherein consideration is given to direct locking of the intermediate portion of the webbing.
2. Description of the Prior Art
There has been proposed a webbing locking deivce wherein, in the case where the tension of an occupant restraining webbing is increased in an emergency such as a collision, this webbing tension is utilized to directly lock the intermediate portion of the webbing, whereby a condition of loosely wound-out webbing is prevented from occurring, so that the occupant can be positively restrained. In the webbing locking device of the type described, the webbing is guided around the forward end of a lock lever pivotally supported on a frame. Tension in the webbing in an emergency is imparted as a pivotal movement of the lock lever, so that this pivotal movement can be utilized to directly lock the intermediate portion of the webbing by means of a pair of friction members. A roller is provided at a webbing contact portion of this lock lever, around which the webbing is guided, to decrease a resistance applied to the movement of the webbing. However, the friction resistance generated at the roller portion is comparatively high, and hence, the resistance against the movement of the webbing in normal use has not yet been sufficiently reduced, thus causing an unsatisfactory winding of the webbing to a takeup shaft and resulting in a high resisting force felt by the occupant when the webbing is wound out.
Furthermore, in the case the roller is used at the webbing contact portion, there is no large variations in tension at the portions before and after the webbing contact portion of the roller and the variations are substantially identical with each other, the tension of the webbing clamped by the pair of the friction members becomes high, so that the webbing cannot be perfectly locked between the friction members in an emergency.